To learn Flashcards
Which gland is responsible for the secretion of mucoproteins into the urethra that help lubricate the passage of semen and neutralise acidic urine.
The bulbourethral gland (also called Cowper gland)
seminal vesicles (also known as the vesicular or seminal glands)
TB medication
Rifampicin
- induces P450
- increase transaminase
- red urine
Isoniazid
- peripheral neuropathy
- heptatotoxicity
Pyrazinamide
- hepatotoxicity
Ethambutol
- visual disturbances
The resting membrane potential of a cell is the difference in electrical potential (voltage) across the plasma membrane and normally ranges from –20 mV to –90 mV depending on the type of cell.
Which membrane-bound protein has the largest role in generating this potential?
K+ ion channels
A 23 year old man with suspected damage to his right median nerve is asked to perform a series of movements in his right hand.)
Which movement is indicated by the blue arrow?
flexion
Which substance can be used as a marker for myocardial infarction
Creatine kinase is sometimes determined routinely as a marker for myocardial infarction in patients with chest pain but this test has largely been replaced by cardiac troponin.
Both the enzyme creatine kinase and the cardiac isoform of troponin would be present in plasma if damage to the heart had occured (these proteins are not normally present in plasma).
A 58 year old man presents to the accident and emergency department with jaundice and abdominal tenderness. He also complains that he has been feeling wheezy and short of breath over the past year. Blood tests reveal that his α1-antitrypsin levels are below the normal range and subsequent genetic testing reveals that he has an inherited form of α1-antitrypsin deficiency.
Over-activity of which enzyme is likly to cause cellular damage in this patient’s lungs as a result of this deficiency?
alpha-1 antitrypsin (AAT) deficiency (AATD), the lack of antiprotease protection results in increased levels of uninhibited neutrophil elastase
gram posiitve bacteria
stain purple
thick peptidoglycan layers
no LPS (endotoxin)
gram negative bacteria
stains red (safranin)
thin peptidoglycan layer
thick LPS (endotoxin)
Neisseria meningitidis is a cause of septicaemia and meningitis and is a Gram negative coccus. The main toxicity of Neisseria meningitidis is due to an endotoxin.
What is this endotoxin?
Which keto acid is used by aminotransferase enzymes to funnel the amino group of other amino acids to glutamate
alpha-ketoglutarate
A healthy 50 year old woman is given a mammogram at a mobile breast screening unit.
What type of prevention does this classify as?
secondary- screening
Secondary prevention aims to reduce the impact of a disease or injury that has already occurred. Secondary prevention aims to detect and treat disease or injury as soon as possible in order to halt or slow its progression
At which stage in meiosis do chiasmata form?
prophase 1
An elderly patient on a medical ward is diagnosed with a Clostridium difficile infection.
What antibiotic is used to treat this infection?
Metronidazole
CORRECT – Metronidazole is effective against anaerobic bacteria and protozoa. C. difficile is an anaerobe.
A 16 month old boy is referred to the ophthalmology unit for evaluation of bilateral leukocoria (white pupils), acute glaucoma and nonreactive pupils. Subsequent testing reveals that the boy has retinoblastoma, a disease resulting from mutation of the retinoblastoma gene.
What is the role of the protein encoded by this gene?
tumor suppressor protein
- stops it dividing untill everything has been checked
A 20 year old man has recently returned from a holiday abroad. He presents to his GP, fearful that he may have contracted HIV. The patient was previously well, with no risk factors for HIV. The GP assesses the patient for signs of an acute HIV infection.
Which of the following features characterises an acute HIV infection?
A flu-like illness with a mild rash
CORRECT – Acute HIV illness usually occurs between 3 to 9 weeks after exposure to HIV. Commonly this is a flu-like illness and may present with lymphadenopathy, a fever, muscle aches and a rash. This risk of acquiring secondary infections only occurs some years late, as the CD4+ T Cell count begins to fall.
genetic variation of down syndrome
(trisomy) of chromosome 21
A 58 year old woman presents to her GP complaining that one of her veins in her leg has become tortuous and twisted. She also complains of itchiness, aching and throbbing along the length of the vein. The skin around the vein feels hard and there are patches that are a purplish colour.
What is the most likely diagnosis?
Chronic Venous Insufficiency
CORRECT – Chronic venous insufficiency (CVI) occurs when blood pools in the veins, straining the walls of the vessels. The weakening of the vessel walls can lead to the veins becoming varicose and the valves of the veins can become incompetent, leading to retrograde flow. The superficial veins are the most vulnerable and symptoms include throbbing, aching and itchiness. However, note that the symptoms occur along the length of the veins. Other complications of CVI include lipodermatosclerosis (hardening of the adipose tissue around the vein), hemosiderin staining (due to the leakage erythrocytes from the vein and the subsequent inflammatory response by macrophages that oxidises haem from Fe2+ to Fe3+), varicose eczema thrombophlebitis (painful thrombosis in the vein due to the inflammatory process) and haemorrhage (bleeding) from the vein. This patient has varicose veins, lipodermatosclerosis and haemosiderin staining in her affected limb, suggesting that she is suffering from chronic venous insufficiency.
Which structure in the image below represents the rete testis?
D
A 62 year old man with ischaemia of his right leg has a femoral embolectomy. The embolus is sent for histological examination and the histology report describes the presence of cholesterol clefts.
Which other condition is this man most likely to have?
A. Abdominal aortic aneursym
The correct answer is abdominal aortic aneurysm as the embolus contains cholesterol indicating that it is likely to have come from an atherosclerotic plaque. The majority of abdominal aortic aneurysms occur as the result of atherosclerosis from which atheroma can break off and embolise to the legs. Atrial fibrillation and left ventricular aneurysm can result in cardiac thrombi which can embolise but which do not contain cholesterol crystals. An atrial myxoma is a benign tumour of the heart, parts of which can embolise, but again the emboli wouldn’t contain cholesterol. Endocarditis (inflammation of the endocardium) usually involves the heart valves. It is characterised by vegetations on the valves which can embolise. The vegetations are composed of thrombus and microorganisms and again do not contain cholesterol crystals.
A 23 year old male involved in a motorbike accident is admitted to the accident and emergency department. The doctor believes the man may have sustained a brachial plexus lesion and assesses motor and sensory function in the man’s right arm.
The anterior rami of which spinal nerve(s) contribute to the middle trunk of this plexus?
C7 only
What is the lifespan of the corpus luteum?.
14 days
Preload
also known as the left ventricular end-diastolic pressure (LVEDP), is the amount of ventricular stretch at the end of diastole.
afterload
resistance left ventricle must overcome
conditions which decrease preload
cardiomegaly
cardiomegaly will reduce
preload
This muscle growth has led to a decreased space within the ventricle chamber for blood at the end of diastole. Therefore, the end diastolic volume (EDV) of the ventricle has decreased and so the woman has diastolic heart failure. As there is less blood in the chamber at the end of diastole, there is less blood that can be ejected in systole. The lack of volume in the ventricles also decreases the stretch of the cardiomyocytes at the end of diastole, leading to a decreased preload which decreases myocardial contractility. Therefore, as the volume in the ventricles is decreased and the preload is decreased, the stroke volume will fall and as stroke volume is used in the calculation of cardiac output (Cardiac Output = Stroke Volume x Heart Rate), the cardiac output will also fall.
afterload will increase due to
hypertension
vasoconstriction
i.e. will have top pump harder
orthosteric vs allosteric
orthosteric- binds to active site
allosteric- binds to elsewhere
Enzymes
lower the activation energy for the reaction they catalyse. Enzymes do not however change the difference in energy levels between reactants and products.
As sperm cells mature they move between the
sertoli cells from the basal compartment towards the adluminal compartment of the seminiferous tubule.
A 28 year old male farmer is taken to the accident and emergency department after spilling a large amount of organophosphorus insecticide over his clothes. He has symptoms of “SLUDGE” syndrome (Salivation, Lacrimation, Urination, Defecation, Gastrointestinal upset & Emesis) resulting from a massive discharge of his parasympathetic nervous system.
Which postsynaptic receptors would be activated at parasympathetic target organs during this massive discharge?
muscarinic ACh receptors
neurotransmitters in the PNS
cohort study
A cohort study is a clinical research study in which people who presently have a certain condition or receive a particular treatment are followed over time and compared with another group of people who are not affected by the condition.
What term is used to describe the cell death of oogonia and oocytes
atresia
A 58 year old man presents to the accident and emergency department with jaundice and abdominal tenderness. He also complains that he has been feeling wheezy and short of breath over the past year. Blood tests reveal that his α1-antitrypsin levels are below the normal range and subsequent genetic testing reveals that he has an inherited form of α1-antitrypsin deficiency.
Accumulation of which substance in this patient’s hepatocytes has led to his jaundice and abdominal tenderness?
protein
α1-antitrypsin deficiency is an autosomal recessive disorder with varying levels of severity in which there are low levels of α1-Antitrypsin, a protease inhibitor which deactivates enzymes released from neutrophils at the site of inflammation. Patients with the disorder develop emphysema as neutrophil elastase released by neutrophils within the lung acts unchecked and destroys parenchymal tissue (α1-antitrypsin normally inhibits neutrophil elastase). Liver disease also occurs as the hepatocytes produce an abnormal version of α1-antitrypsin, which is incorrectly folded. This abnormal α1-antitrypsin polymerises and cannot be exported from the endoplasmic reticulum, meaning that it accumulates inside the liver cells. This causes hepatocyte damage and eventually cirrhosis
An 80 year old man with heart failure has developed symptomatic atrial fibrillation with a rapid but irregular heart rate. The patient is having a review of his medication by the cardiologist who decides to prescribe a drug which is a positive inotrope but will slow conduction at the AV node to improve his condition.
What type of drug will he prescribe?
cardiac glycoside
A cardiac glycoside inhibits Na/K ATPase which then leads to decreased functioning of the Na/Ca exchanger. This leads to a build-up of calcium ions within the cell which leads to an increase in the strength of contraction of the heart. Cardiac glycosides also increase vagal activity on the heart which slows conduction at the AV node.
mechanism of viagra (sildenafil citrate)?
inhibition of cGMP breakdown, leading to icnreased NO production and vasodilation
- Sinusoidal relaxation
- Arterial dilation- blood rushes into corpus cavernosum and spongiosum= erection
- Venous compression
label this
A- corona radiata
B- ovum cytoplasm
C- zona peluccida (sperm fuses here)
D- nucleus
binding of the sperm surface to ………..triggers the acrosome reaction
ZP3 glycoprotien on zona pellucida
- Seminal vesicles
- 60% of volume
- Alkaline fluid (neutralises the acid: male urethra and female repro tract)
- Fructose, prostaglandins, clotting factors (semenogelin)
Prostate gland
- 25% volume
- Milky, slightly acidic fluid
- Proteolytic enzymes (breakdown clotting proteins, re-liquefying semen in 10-20 minutes)
- Citric acid, acid phosphatase
Bulbourethral glands (COwpers glands)
- Very small volume
- Alkaline fluid
- A mucous that lubricates the end of the penis and urethral lining
Which statement most correctly describes a thyroglossal cyst?
moves on tongue protrusion
A 45 year old man attends his GP surgery for a routine health check. He weighs 70kg, has no cardiovascular pathology, and is currently at rest.
What value would be the best estimate of the patient’s current cardiac output?
4.9l/min
– Cardiac output (CO) can be calculated from heart rate (HR), and stroke volume (SV) using the following equation: CO = HR x SV. The resting HR and SV values for the average “textbook” male described above are 70bpm and 70ml, therefore giving a cardiac output of 4.9L/min (sometimes rounded to 5L/min).
A 58 year old man with unstable angina is prescribed aspirin. Aspirin non-competitively inhibits the enzyme cyclooxygenase, decreasing the ability of platelets to produce thromboxane A2, and therefore diminishing their ability to aggregate. Ibuprofen is also a cyclooxygenase inhibitor but is a competitive rather than a non-comepetive inhibitor of the enzyme. The graph below shows kinetic data for the reaction catalysed by cyclooxygenase both in the presence and absence of aspirin and ibuprofen.
Which kinetic curve corresponds to the reaction in the presence of ibuprofen?
Curve 2
CORRECT – A competitive inhibitor competes with the substrate for the active site of the enzyme: This means that increasing the concentration of substrate will decrease the chance of inhibitor binding to the enzyme. Hence, if the substrate concentration is high enough the enzyme will reach the same Vmax as without the inhibitor. However, it will require a higher concentration of substrate to achieve this and so the Km of the enzyme will also be higher.
21 year old man dives into a shallow river and hits his head on the riverbed. His head is not hyperextended or hyperflexed during the injury. The man has pain in his upper neck, his pupils are decreased in size (miosis), his eyelids are partially drooped (ptosis) and his eyeballs have a sunken appearance (enophthalmos).
What type of injury has the man most likely suffered?
jeffersons fracture
he man’s history suggests that he has incurred a significant axial loading of his vertebral column (this was incurred when he hit his head on the riverbed). This form of loading often leads to damage to the C1 vertebra, causing it to burst open (like a polo mint). The damage to this vertebra often leads to patients attending an emergency department holding their heads in their hands. Fortunately, the ‘bursting open’ of the bone fragments reduces the likelihood of impingement on the spinal cord. This fracture therefore typically causes pain but no neurological signs. Occasionally, however, there may be damage to the arteries at the base of the skull leading to secondary neurological sequelae e.g. ataxia, stroke, or Horner’s syndrome. Horner’s syndrome is damage to the sympathetic trunk and leads to a decreased pupil size (miosis), partially drooped eyelids (ptosis), sunken eyeballs (enophthalmos) and decreased sweating (anhidrosis). Therefore, it appears that the man is suffering from Horner’s syndrome.
What proportion of plasma thyroid hormone (T3 and T4) is “free” in plasma (i.e. not bound to proteins such as Thyroxine-binding globulin or albumin)?
1%
outline how T3/T4 production is stimulated
- the hypothalamus release thyroid releasing hormone (TRP)
- TRP stimulates the anterior pituitary to release Thyroid stimulating hormone (TSH)
- TSH stimulates the thyroid to release T3/T4
From which amino acid does the body synthesise the hormone adrenaline?
tyrosine
A 58 year old woman presents to her GP complaining of pain in her left leg that has been worsening over the last few months. She had previously been able to relieve the pain by rest but recently has found that the only way to relieve the pain is to hang her left leg out of bed at night. She is a smoker and has a BMI of 33.
What is the most likely diagnosis?
acute limb ischaemia
A patient is infected with HIV. Following an acute illness when he was diagnosed, he has remained clinically well for the last year.
What cell or cellular product is responsible for maintaining this period of clinical health over the last year?
HIV specific CD8 T cells
Summary of manifestations of refeeding syndrome
- Disturbances of body fluid distribution
- Hypophosphatemia
- Hypokalaemia
- Hypomagnesaemia
- Thiamine deficiency
- Altered glucose metabolism
at what vertebral level would you find the right kidney
T12-L3
where is the hilum of the kidney found
L1
at what vertebral level would you find the left kidney
T11/12- L2/3
in response to hamorrhage, which of the following is activated to cause decrease in GFR
sympathetic nervous system
what happens to prevent increase in the pressure in the glomerular capillarys
constriction of afferent arteriole
a blockage in ure outflow e.g. by urinary stone, causes increase in pressure in bowmans space. how would this affect net glomerular filtration pressure and gfr?
decrease
what term best describes bowmans capsule oncotic pressure
neglible
what would happen to GFR if the glomerular oncotic pressure decreased
GFR would increase
which substance normally filtered in the kidney would have a filtered rate of urinary excretion that is almost always idnetical to GFR
creatinine
what is used to estimate renal plasma flow
PAH- para-aminohippuric acid
filtration rate =
conc of substance in plasma x GFR
calculate
filtration rate = conc in plasma x GFR
= 0.01 x 125
=1.25 mg/min
calculate
C= [V]x X V/ [P]x
CHECK EVERYTHING IS IN THE SAME UNITS
c= 1.35 x1/0.01
in clearance calculation what are flow rate units in
ml/min
in clearance calculation what are concentration units in
mg/ml
calculate
excreted creatine =
conc of urine creatinine x flow rate
filtered creatinine rate =
plasma creatinine x GFR
excretion =
filtered- reabsorbed +secretion
outline changes to the kidney in DKA
Hyperfiltration/ capillary hypertension
Happens before all over changes
Glomerular basement membrane thickening
Mesangial expansion
Podocyte injury
Glomerular sclerosis
which Abx target gonorrhea (gram negative cocci) and chlamydia (gram negative rod)
Azithromycin and ceftriaxone
Target gonorrhoea and chlamydia
One Abx can augment (make greater) the effect of the other
treatment of BV (gardenella vaginalis)
metronidazole
how does H.pylori (gram neg rod, microaerophil) cause damage to the stomach
- CagA gene injected into stomach lining = inflammation- increased risk of stomach cancer
- VacA secretion- toxic
- Also secretes- mucinase, protease and lipase= damage mucus layer of stomach
- causes over secretion of gastrin- too much acid–> duodenal epithelia metaplasia to gastric like epithelia
- OVERALL DAMAGE TO MUCUS LAYERS OF STOMACH
Symptoms of peptic ulcer disease
- Epigastric pain–> back pain (burning pain) following meals
- Pain at night
- Duodenal
- Resulting from bleeding: haematemesis and melaena–> anaemia
- Early satiety and weight loss
location of peptic ulcer disease
- duodenum (most common)
- H.pylori found in 100%
- gastric ulcers (lesser curvature and antrum)
- H pylori
- NSAIDS–> decrease prostaglandin synthesis
- Smoking –>contribute to relapse
- Massive physiologic stress (e.g. burns)
Stomach protective mechanism
Rich blood supply and prostaglandins increase blood flow (higher HCO3) support mucus layer–> generally protective.
epithelial cells are replaced regularly to protect the stomach.
Antral colonisation by H.pylori–
over activity of G cells- stimulates parietal cells–> too much acid produced–> makes chyme more acidic damaging duodenum (more gastric like duodenum- can be colonised by H pylori- duodenal ulcers)
Absorption of lipids
- Lipids diffuse down conc gradient into intestinal epithelial cells (in the micelle)
- Inside cell re-esterified back to:
- Triglycerides
- Phospholipids
- Cholesterol
- These reformed lipids are packed with apoproteins to form chylomicrons
- Chylomicrons exocytosis from basolateral membrane
- Too large to enter capillaries
- Enter lymph capillaries
- Travel through lymphatic system
- Re-enter vascular circulation via the thoracic duct
Bile acid independent
- Secreted by duct cells
- Similar alkaline solution to pancreatic duct cells
- Stimulated by secretin
starch
- Polysaccharide (long chain of glucose)
- Consists of Straight chains of glucose- amylose
- Held together by alpha 1-4 bonds
- Branched chains of glucose- amylopectin
- Held together by alpha 1-6 bonds
amylopectin digestion
Break down 1-4 bond- leaves us with shorter but still branched molecule –>alpha dextrin- due to amylase not having an effect on 1-6 bonds
Need isomaltose to breakdown alpha 1-6 binds
which other zymogens does trypsin activate
More trypsinogen–> trypsin
Chymotrypsinogen –> chymotrypsin
Proelastase –> Elastase
Procarboxypeptidase A –> Carboxypeptidase A
Procarboxypeptidase B –> Carboxypeptidase B
These enzymes can be grouped into: Endopeptidases or Exopeptidases
Endopeptidases
produce smaller polypeptides- break down bonds in the middle of the chain
Trypsin
Chymotrypsin
Elastase
exopeptidases
break off bonds at the end of the chain
Carboxypeptidase A and B
Q
coeliac disease is an immunological response to which fraction of gluten
gliadin
cirrhosis
Permanent irreversible damage to the liver, impairment of liver function and distortion to the architecture of the liver. In response to chronic inflammation
Inflammation –> fibrosis and hepatocyte necrosis –> bands of fibrous tissue form which causes nodules to form (think of her balloon analogy)
Alcoholic hepatitis
- Years of exposure (initially reversible)
- Presence of inflammatory cells alongside fatty changes
- More serve symptoms
- RUQ pain
- Jaundice
- Oedema
- Ascites
- Leads to cirrhosis
Non-alcoholic fatty liver disease (NAFLD)
Insulin resistance
Accumulation of TAG and other lipids within hepatocytes
Specific to inflammation present= NASH- Non-alcoholic steatohepatitis- inflammation
iron deposition i.e.
copper deposition i.e.
hereditary haemochromatosis
wilsons
autoimmune heptitis
autoantibodies which attach liver cellls e.g. hepatocytes ASMA, ANA
hereditary haemochromatosis
Increased absorption of iron
Increased deposition of iron in the liver
Due to increased levels of ferrite
Recessive
Risk of hepatocellular carcinoma
Treatment: venesection- remove amount of iron in circulation
Can also affect pancreas
portal hypertension
increase in the pressure within the portal vein (the vein that carries blood from the digestive organs to the liver). The increase in pressure is caused by a blockage in the blood flow through the liver.
e.g. cirrhosis reduces expansibility of liver
oesophageal varices
- Upper 2/3 drains into oesophageal veins- goes through the azygous drains into the superior vena cava (systemic circulation)
- Distal portion drains into the left gastric vein- drains into the portal vein (portal circulation)
- At the junction where there are veins draining into the main systemic circulation (SVC) is where the pressure builds up.
- Veins are superficial- therefore become dilated–> easy to rupture
- Significant Haematemesis
Complications of gall stones
Biliary colic
acute cholecystitis
ascending cholangitis
acute pancreatitis
BILIARY COLIC
Gall stones happily sitting within gall bladder, but can cause sudden onset of RUQ pain typically a few hours after eating a fatty meal
Due to cholecystokinin (CCK) release after meal, which causes the gall bladder contract and push a gallstone up against the neck of the gall bladder- temporary obstruction of biliary duct
Constant pain- can last for a long time and then ease for a while
Treatment- pain relief and removal
Acute cholecystitis
RUQ pain- caused by full impaction of stone in cystic duct
Inflammatory features
Positive Murphy sign place a hand on right side of the patients stomach and ask them to take a deep breathe in- will push gall bladder down and cause them to take a sharp breathe in pain (wont happen on left hand side)
Treatment- pain relief and Ab, will need to be removed
Ascending cholangitis
Statis due to blockage of Common Bile Duct by stone
Infection of biliary tree
Charcots triad (Inflammation, RUQ pain, jaundice (when stone reaches common bile duct))
Acute pancreatitis
Stone in common bile duct after the point when the pancreatic duct has joined the common bile duct
Autodigestion of pancreas- due to enzyme not being able to be released into duodenum
Symptoms
Epigastric (back) pain
Vomiting
Cullen’s and Grey Turners sign
Look for raised levels of amylase and lipase in the blood
CT scan
ALP -alkaline phosphatase
- Bile ducts in the liver blocked (cholestasis)
- Can be high in children that are growing quickly/ also malignancy of bone
- Gamma-glutamyl transferase - another enzyme which will confirm if the raised ALP are caused by a damaged or obstructed bile duct as opposed to the bone
Briefly describe the potential effects of excess alcohol on the Liver over a period of:
- Weeks
- Years
- Decades
- Weeks- fatty liver (reversible)
- Years- alcoholic hepatitis
- Decades- cirrhohis
describe the effects of portal hypertension on kidney function in Hepatorenal syndrome
decreased renal function
activation of symapthetic nervous system results in renal vasoconstriction and therefore reduced renal blood flow, reduced GFR - renal failure , even acute tubular necrosis (ATN)
- Explain to a friend (in stages) how chronic alcohol misuse can eventually result in the formation of abdominal ascites
increased fat depsoiton in the liver
overtime increase in inflmamaortry cell influx
chronic inflammation
cirrhosis
decrease expandability of liver
compressed protal vein
increased portal hypertension
less albumin produced
ascites
oculomotor nerve lesion
down and out
trochlear nerve lesion
corneal reflex
afferent- trigeminal Va
efferent- facial- oblicularis oculi
glossopharangeal nerve
Peripheral chemoreceptors are located in the carotid and aortic bodies and are innervated by the glossopharyngeal nerve
vagud nerve
how do we hear
- Auricle and external auditory canal focus and funnel sound waves to TM which vibrates
- Stapes vibrates on oval window so movement of fluid in cochlear
- Fluid movement sensed by stereocilia in cochlear duct (spiral organ of corti)
- Movement of fluid triggers action potentials in cochlear part of CN VIII
- Primary auditory cortex in temporal lobe
if septal/ pinna haematomas are not treated
how do local anaesthetics work
What is the accomodation reflex?
Focusing near objects requires greater refraction of light
- Contraction of the pupils
- Convergence of the eyes
- Thickening of the lens to become biconvex by contracting ciliary muscle so suspensory ligaments loosen
muscles of the iris
sphincter pupillae,
muscles of the lens
ciliary muscles
suspensory ligaments
What are the properties of the pre- and postganglionic neurones in the sympathetic branch of this division of the nervous system?
B
postganglionic axons are not myelinated
weaknesses of the sick role analogy
A 62 year old man undergoes an inguinal hernia repair. The wound heals poorly and a significant amount of granulation tissue is produced.
Which of the folowing is NOT true regarding granulation tissue?
A. Cells within it contract and pull the wound edges together
B. Cellularity decreases over time
C. Proportion of collagen increases over time
D. Usually lasts about 3 months
E. Vascularity increases over time
The vascularity of granulation decreases over time as vascular channels regress. All of the other options are true.
A UK Medical School is considering introducing a Health Enhancement Programme for their Medical Students based on the ESSENCE model.
outline the ESSENCE model
Education
Stress management
Spirituality
Exercise
Nutrition
Connectedness
Environment
=7 PILLARS OF HEALTH
types of skeletal muscle
A research study found that epidural anaesthesia significantly decreased peripheral resistance in patients undergoing femorodistal reconstruction.
Which type of blood vessel normally contributes the most to this type of resistance?
arterioles
outline what happens to the larynx when we swallow
- Hyoid bone elevated and moves anteriorly by suprahyoid muscles
- Larynx moves up and forward
- Tongue pushes epiglottis posteriorly and aryepiglottic muscles contract
- Narrowing laryngeal inlet
- Brining epiglottis from a vertical to a more horizontal position (longitudinal pharyngeal muscles)
- Directs food into the piriform fossa into the oesophagus
- Closure of vocal cords (glottis)
vagus nerve innervation to the larynx summary
Autonomics will also be delivered via CN X to mucosal glands within the larynx
recurrent laryngeal nerve route
- arises distally from the vagus
- passes anteriorly to then loops under right SCA (superior cerebellar artery) and on left, arch of the aorta
- asends in tracheo-oesophageal groove
- close anatomical relationship with thryoid gland and inferior thyroid arteries supplying the gland
hoarse voice caused by
damage to the superior laryngeal nerve
The internal branches provide sensory innervation of the larynx above the vocal cords, whereas the external branches provide motor innervation to the cricothyroid muscle, a tensor of the vocal cords.
vocal cord palsy, trouble coughing etc
recurrent larangeal palsy
example of causes of vocal cord palsies due to injruy to the RLN
Thyroid sugery- RLN closely related to inferior thyroid artery
Aortic arch aneurysm (left RLN)
Cancer involving apex of lung (right RLN) (pancoast tumour)
Disease or surgery involving larynx, oesophagus or thyroid
Unilateral lesions lead to unilateral vocal cord palsies
Hoarse voice
Ineffective cough
the paralysed vocal cord assumes a paramedian position (comes across central line)
- between fully abducted and fully adducted
- often the contralateral side will compensate in tiem 9crosses midline to meet vocal cord on affecte dside)
Bilateral lesions of the RLN
Both vocal cords paralysed and in paramedian position
Narrow glottis
Significant airway obstruction… emergency surgical airway e.g. cricothyroidotomy, tracheostomy
summary of larynx
vestibular ligament= false vocal cords
vocal ligament= true vocal cords (stratified squamous)
stridor vs wheezer
stridor= upper airway- inspiratory sound
wheeze= lower airway- expiratory sound
Definitive airway: Intubation
endotracheal tube
Why do you think the girl sitting with her head held in a sniffing position and what does the hard inspiratory noise suggest?
Head tilt chin lift
Holds the airway more patent
Maintain airway
Stridor= airway obstruction in the upper respiratory tract
movement of which cartilage moeves the vocal cords
arytenoid cartilage
hyperkalaemia treatment
calcium gluconate- stabilises heart muscles preventing arrythmia
insulin dextrose- drives potassium into cells (glucose to prevent hypoglycaemia)
calcium resonium- increased excretion from the body
inhalation uses which muscles
external intercostals and diaphragm
name two accessory muscles of expiration
internal intercostals
abdominal wall muscles
name 4 accessory muscles of inspiration
SCM
Serratus anterior
Pectoralis major
fluid in alveoli increases
surface tension (decreasing compliance)- limits expansion
- surfactant reduces surface tension
smaller alveoli
surfactant molecules clsoer together- better at disrupting warer molecules
- less likely to collapse due to have a smaller volume
larger alveoli
surfactant molecules further apart - less effective at disturbing the surface tension pressure inside therefore bigger alveoli stays high despite it being bigger
why do big alveoli not collapse
i.e. pressure does not drop despite increased ‘volume’ of the alveolus, as the increased pull ‘inwards’ from the surface tension counters this
- If pressure remains high in bigger alveoli, keeps pressures equal to smaller alveoli
- Prevents collapsing of small alveoli into big alveoli
how do bronchioles stay open on expiration if they have no cartilage
radial traction
outward tugging action of the surrounding alveolar wall on bronchioles- tether them open
- Prevents collapse of bronchioles on expiration
Why is airway obstruction worse in expiration than inspiration?
During inspiration the volume of the lungs increases so the pressure in the lungs decreases (more negative).
During expiration, the volume of the lungs decreases meaning the intrapulmonary pressure goes up, pushing on the bronchioles which don’t have cartilage- must have radial traction from the alveolar network.
which disease shows decreased lung compliance and therefore higher elastic recoil
interstitial lung disease
which disease cause increase compliance and decreased elastic recoil
asthma and COPD (obstructive)
↑airways resistance and, in emphysema decreased elastance secondary to loss elastin – compliance actually increased
Resorption collapse
- Due to obstruction of large airway e.g. lung cancer, mucous plugs
total pulmonary ventilation (mnute volume)=
tidal volume X respiratory rate
alveolar ventilation (minute ventilation)=
(tidal volume - dead space) x resp rate
a shift to the right on the oxygen dissociation curve represents
decreased affinity of the haemoglobin for oxygen and hence an increased tendency to give up oxygen to the tissues.
where is most of HCO3- made
the RBC
the high [HCO3-] cannot come from CO2 alone in plasma- not enough dissolved CO2 in plasma to create this much HCO3-
why is HCO3- production in the RBC much faster than the plasma
Reaction speeded up by Carbonic anhydrase (CA) enzyme present in RBC but not present in plasma
How is the reaction which produces HCO3- in the RBC kept in the forward direction
the products are mopped up
- HCO3- is transported out of the RBC by the chloride/ HCO3- exchanger
- creates a plasma conc of 25 mmol/L HCO3-
- H+ is bound to Hb
What happens when venous blood arrives at the lungs
- Hb picks up O2 and goes into R state ( due to higher pO2)- lower affinity for H+
- This causes Hb to go into the relaxed state and give up the extra H+ it took on at the tissues
- H+ reacts with HCO3- to form CO2
- Reaction push to the left
- CO2 diffuses out of the blood into the alveoli
- CO2 is breathed out
haldance effect
the higher the pO2 the lower affinity Hb has for CO2- therefore given up at lungs
% of dissolved CO2 transported to the lungs
10%
% of bicarbonate transported to the lungs
60% of CO2
% of dissolved carbamino compounds transported to the lungs
30%
bohr effect
the decrease in the oxygen affinity of a respiratory pigment (such as hemoglobin) in response to decreased blood pH resulting from increased carbon dioxide concentration in the blood.
summary of the cartilages associated with each arch
nerve associated with each pharangeal arch
1- trigeminal (muscles of mastication)
2- facial nerve (muscles of facial expression)
3- glossopharangeal
4- vagus
6- vagus
diabetes inspidus caused by
insufficient production of ADH- therefore inability to reabsorb water in certain parts of the nephron
symptoms:
Polyuria
Polydipsia
Low urine osmolality (i.e. dilute urine)
Pharmacological management: SUI
duloxetine
Combined noradrenaline and serotonin uptake inhibitor
Increased activity in the striated sphincter during filling phase
Not recommended by NICE as first line or routine second-line treatment but may be offered as alternative to surgery
male artificial urinary sphincter
gold standard
used when urethral sphincter deficiency
neurological
post-DXT or surgery
Cuff simulates action of normal sphincter to circumferentially close the urethra
mechanical (hydraulic) device
Initial management: UUI
- Schedule of voiding
- Void every hour during the day
- Must not void in between – wait or leak
- Intervals increased by 15-30 minutes a week until interval of 2-3 hours reached
- At least 6weeks duration
Pharmacological management UUI
- Anticholinergics - β3-adrenoceptor agonist (licensed in 2014) - Intravesical injection of Botulinum toxin
act on muscarinic receptors (M2, M3)
side effects due to affects on M receptors at other sites
- M1 - CNS, salivary glands
- M2 - heart smooth muscle
- M3 - smooth muscle (ocular and intestinal), salivary glands
- M4-CNS
- M5 - CNS, eye
- Many brands e.g. Oxybutynin, Solifenacin
medical treatment of BPH
Alpha blockers (internal sphincter), relax smooth muscle at bladder neck and within prostate
Finasteride (alpha reductase inhibitor)
Prevents the conversion of testosterone to the more potent androgen dihydrotestosterone
Surgical treatment of BPH
Transurethral resection of prostate (TURP)
Physically enlarged urethra
Diuretic renography (MAG3)
FUNCTIONAL TEST
Give furosemide to increase diuresis
Can see that in a normal urinary tract after giving furosemide you get a flow of liquid
In obstructed giving furosemide will not change activity
predisposing factor of Urolithiasis
dehydration
calcium oxalate stones
most common
- associated with hypercalcemia and primary hyperparathryoidism and hyperoxaluria
Budd-Chiari syndrome
is caused by blood clots that completely or partially block blood flow from the liver.
Wilms’ tumor
is a rare kidney cancer that primarily affects children.
